Method of supplying gas to gas consumers

ABSTRACT

A method for supplying gas to gas consumers, which method resides in forming a storage reservoir above a gas-saturated water-bearing horizon under development, filling the storage reservoir thus-formed with gas by periodically subjecting the horizon under development to extraneous effects, followed by delivering the gas to gas consumers. Extraneous effects can be exerted by generating elastic vibrations, providing a pressure difference, raising the temperature, applying electromagnetic field oscillations, or combining these factors. If the method of the invention is used in seismically active areas or in regions exposed to effects of elastic vibrations, its efficiency is considerably increased.

FIELD OF THE INVENTION

The present invention relates to methods for supplyign gas to gasconsumers, and, more specifically, to a method for supplying gasconsumers with gas by forming a storage reservoir, preferably inimmediate vicinity to the gas consumer, filling it up with gas extractedfrom gas-saturated water-bearing horizons, followed by reclaiming thegas at will.

The invention may be advantageously used for creating a gas pool readyfor use, and for supplying therefrom gas to gas consumers in a simpleand dependable manner.

DESCRIPTION OF THE PRIOR ART

It is common knowledge that gas is produced from gas, gas-condensate,and oil-gas-condensate deposits at areas of their naturally occurringformation which takes long (in geologic terms) periods of time, whereasgas consumers (such as industrial enterprises, municipal services, etc.)are normally supplied with gas using the following procedure: gasproduction from gas deposits--in-situ gas preparation--gastransportation to gas-consuming areas in which storage reservoirs areformed and filled with gas to become a gas source from which gas userscan be provided with gas at will.

To solve the above-formulated problem, in the prior art frequent use was(and is) made of providing an underground reservoir for storing gas inthe vicinity of areas where it is consumed. It is exactly this techniquethat is described, e.g. in a book by Trebin F. A., Makogon Yu. F. andBasniev K. S. NATURAL GAS PRODUCTION, Nedra Publishers, Moscow, 1976,p.368. It is a technique known in the prior art to use underground trapreservoirs developed as a result of naturally occurring geologicprocesses in prospecting for naturally formed gas deposits and forassessment of gas reserves according to seam pressure drops. Forinstance, USSR Inventor's Certificate No.1,032,171 (published on Jul.30, 1983) proposes a method whereby a trap disposed above a gas depositis used for assessment of gas reserves in accordance with seam pressuredrops in the trap in the course of passage of a gas flow through thetrap, but without ever reclaiming the gas passed therethrough.

USSR Inventor's Certificate No.442,287 (published on Nov. 21, 1974)provides a method whereby free gas is liberated from gas-hydratedeposits by subjecting them to the effect of vibrations generated by anelectromagnetic emitter or by a magnetostrictive drill inserted into agas well.

Equally known in the prior art (Ref. USSR Inventor's CertificateNo.859,606; published on Oct. 5, 1981) is a method for operating an oilwell, whereby a source of acoustic vibrations is immersed into the oilwell for the purpose of liberating gas from the liquid column in the oilwell, whereafter the oil well is operated in the gas lift operationalmode.

Also known in the prior art is a method for gas production by causingthe gas to be transported by the flow of the underground stratum (seam)liquid to the day surface, followed by separating the gas from theliquid (Reference Book on Oil Production, NEDRA Publishers, Moscow,1974, pp.511-512).

U.S. Pat. No. 4,040,487 (published on Aug. 9, 1974) and U.S. Pat. No.4,116,276 (publ. on Sep. 26, 1978) are directed to a method forincreasing the natural gas production from a water-bearing horizoncontaining water and gas by pumping water therefrom.

Also known in the prior art are methods for recovering hydrocarbons fromtheir naturally occurring deposits using vibratory or acoustic effects(Ref. U.S. Pat. No. 3,952,800 issued on Apr. 27, 1976; U.S. Pat. No.4,060,128 issued on Nov. 29, 1977; 4,114,689 issued on Sep. 19, 1978;U.S. Pat. No. 4,417,621 issued on Nov. 29, 1983), accompanied withthermal effects (Ref., e.g. U.S. Pat. No. 4,049,053 issued on Sep. 20,1977), or using electromagnetic field effects (Ref. U.S. Pat. No.4,084,638 issued on Apr. 18, 1978; U.S. Pat. No. 4,164,978 issued onAug. 21, 1979; U.S. Pat. No. 4,638,863 issued on Jul. 25, 1986; and U.S.Pat. No. 4,705,108 issued on Nov. 10, 1987).

However, none of the above-cited patents makes provision for gasliberation from gas-saturated water-bearing seams, for the formation ofstorage reservoirs, for development of new gas fields, etc.

The main disadvantages inherent in the prior-art methods reside in thefollowing:

in using storage reservoirs for underground storing of gas in thevicinity of gas consumers, such reservoirs are filled with the earlierextracted gas which had been transported preliminarily fromgas-producing regions situated, as a rule, at great distances from thegas consumers. This system of gas supply to gas users involvesconstruction of trunk pipelines, pump stations, etc., which involveslarge financial, material, power, etc. expenses;

extraction of stratal gas-saturated water to the day surface, followedby gas separation is, for practical purposes, an unprofitable business,since it involves moving large quantities of liquid and is encumberedwith many other troubles brought about by a high mineralization ofstratal waters;

gas extraction from a water-bearing horizon by reducing its pressureowing to constant pumping-out of water for a long period of time (atleast for a year) suffers from the same disadvantages as stated above(water must be pumped out of each well in quantities of from 15 to 25×10barrels per day), slow recovery of gas, and incomplete retrieval of gasfrom a horizon;

The remaining citations characteristic of the prior-art level areassociated with natural hydrocarbon deposits already under development.

Meanwhile, hydrocarbon deposits under development are being graduallyexhausted, while newly discovered deposits are located, as a rule, atconsiderable distances from industrial areas and from other regionswhere natural gas is consumed, and gas transfer to them constitutes alabour-intensive and cost-intensive problem. As to the formation of newdeposits due to processes naturally occurring in the Earth's depths, ittakes geological periods to form them.

In this connection, the problem of industrial recovery of gas from othergas sources becomes more and more acute, in particular, the problem ofgas production from gas-containing water-bearing horizons, althrough,until the advent of the present invention, direct gas recovery from suchhorizons was regarded as impossible or, at least, industriallyunrewarding. The point is that such horizons occur rather frequently innature and often may be found in the vicinity of gas-consuming areas.Not infrequently such horizons merge together to form vast subterraneanfields occupying fairly considerable surface areas reaching severalthousands of square kilometers and, possibly, even more. Their use forgas recovery, particularly in those areas where natural gas andoil-gas-condensate deposits are absent, would make it possible toconsiderably increase the tonnages of gas produced and to facilitatesolution of the problem of supplying consumers with gas.

Until the advent of the present invention, the commercial-scale gasproduction from water-bearing horizons has not been paid due attentionbecause of excessive labour input and poor efficiency of the hithertoknown methods.

The present invention is aimed at solving this problem.

SUMMARY OF THE INVENTION

It is the object of the present invention to develop a method forsupplying consumers with gas from gas-saturated water-bearing horizons,for increasing the volumes of gas extracted from gas reserves, and forreducing the expenses associated with shipments of gas. It is anotherobject of this invention to use natural or artificial sources of elasticvibrations occurring in an area with a view to bringing down powerconsumption involved in the gas production from such horizons.

The above-formulated objects are accomplished by the formation of astorage reservoir above a gas-saturated water-bearing horizon and to thefilling it with gas by subjecting the gas-saturated water-bearinghorizon to the periodic action of various effects. It has beenestablished that it is exactly the combined use of these factors thatmakes it possible to efficiently and reliably extract gas fromgas-saturated water-bearing horizons and to store it in the reservoirthus-formed for stable gas supply to gas users.

Effects periodically exerted onto a gas-saturated water-bearing horizonmay be achieved by generating elastic vibrations in the horizon, e.g.elastic vibrations induced by explosions and/or with the aid of a sourceof acoustic, vibratory or seismic waves.

Such effects may also be achieved by raising the temperature by, e.g.injecting hot steam into a water-bearing horizon (particularly throughan injection well) or at the expense of the heat generated by a workingelectric heater sunk into a horizon, e.g. through a gas extraction well.It is preferable to use thermal effects when gas is found in the form ofgas hydrates.

Effects on a gas-saturated water-bearing horizon may be also achievedwith the help of an electromagnetic field, e.g. by electric dischargesemitted by a spark-gap device or by electrodes immersed into awater-bearing stratum and supplied with constant voltage or, e.g. withfrequency-modulated voltage.

Elastic vibrations and electric current influence not only the processestaking place in fluids, but also exert their effect upon the collectingproperties of a geological seam (stratum). For instance, as a result ofsubjecting a water/gas-saturated horizon to treatment with electricpulses there are generated thermal, electromagnetic, andphysico-chemical effects (e.g. electric current pulses provoke phenomenaof electrolysis, electroosmosis, etc.), as well as elastic disturbances,primarily shock waves conducive to cracking of a collector seam, toacceleration of the flow of liberating gas towards gas wells, and tomore complete gas recovery from seams (strata).

By subjecting gas-saturated water-bearing horizons to the intermittenteffect of elastic vibrations it is possible to significantly speed upthe gas liberation processes, and to boost up and intensify the gas flowtowards a storage reservoir. With the help of vibrations it is alsopossible to control gas flow conditions. Using low-frequency vibrationswithin the range of from 0.1 to 60 Hz, it is possible with the aid of asingle source of seismic vibrations located on the surface to exerteffect simultaneously on several gas-saturated water-bearing horizonsoccupying considerable surface areas and lying at significant depths.Use of such vibrations also ensures the fullest possible gas yield.

It is equally possible to achieve periodic de-gassing effect on agas-saturated water-bearing horizon by providing a pressure difference,for instance, by organizing partial discharge of water from thewater-bearing horizon.

It is also possible to exert periodically effect on a gas-saturatedwater-bearing horizon by making simultaneous use of all theabove-mentioned factors taken in various combinations and using varioussources of, such effects depending on the specific operationalconditions. In doing so, the mechanism and the extent of the effectexerted onto an object by such combined factors are determined not by amere sum total of the mechanisms of each factor, but rather byqualitatively and quantitatively new effects produced by suchcombinations. The efficiency of the method in accordance with thepresent invention is improved by using combined effects. Thus, forinstance, if the effect of elastic vibrations is combined with theeffect of a reduced pressure, the degassing effect becomes substantiallymore pronounced and manifests itself much more quickly, than in theevent of using individually each of the above-mentioned factors. Apartfrom the above-enumerated factors, use may be made of any other factorsknown in the art and conducive to gas liberation from gas-saturatedwater-bearing horizons.

The periodicity of effects is dictated by the totality of specificparameters, namely: parameters describing the current condition of agas-saturated water-bearing horizon (including the pressure,temperature, specific volume), its composition, physical andphysico-chemical properties (relaxation properties included) of fluidsand formations, their alterations under the effect of various factorsapplied, collecting and other properties of rocks, resonantcharacteristics of strata (seams), degree and filling rate of a storagereservoir, gas take-off for users' needs, and other factors.

As a gas-saturated water-bearing horizon is subjected to the effect ofthe above-described factors, gas liberation starts therein, the gasbeing liberated in diverse forms: in dissolved state, in free state, asgas bubbles, as gas hydrates, etc. However, gas liberation from suchhorizons takes palce non-uniformly, which fact is associated with theirgeologic structure and gas saturation degree. Moreover, thenon-uniformity of gas liberation cannot be eliminated by controlling theperiodicity of de-gassing effects. It is this non-uniformity that makesit impossible to use the gas being liberated for immediate supply of gasusers and even for most modest economically effective gas transportationbecause of abrupt gas pressure drops and raises, and of sharp changes ingas flow rates, whereby the combined use of the above-mentioned factorsis made necessary.

In accordance with the present invention, apart from the periodicdegassing effects on a gas-saturated water-bearing horizon, use is made,in association therewith, of the expedient of forming at least onestorage reservoir above this horizon. The term "storage reservoir" isused here to denote a certain volume capable to receive the liberatedgas, e.g. subterranean voids and cavities, and to denote any spacevolume possessing a greater porosity and gas permeability than those ofa geologic cover which surrounds a gas-saturated water-bearing horizon.

The term "formation" depending on specific geologic conditions, maydenote most diverse operations. This may be a discovered structure, inwhich--after drilling and sealing the drilled boreholes--a reservoir iscreated, e.g. by blasting, by thawing down permafrost rocks, by washingout caverns in salt deposits, clays, etc., by using additionalreinforcement of walls and, in particular, vault by any conventionalmethods. There may be formed several storage reservoirs disposed abovedifferent gas-saturated water-bearing horizons. Moreover, these storagereservoirs may be brought in hydrodynamic communication with each other.

In the process of periodically acting upon a gas-saturated water-bearinghorizon and of gas liberation therefrom, a storage reservoir thus-formedis gradually filled up. Nor does the present method rule out thepossibility for directing the gas liberated from a water-bearing horizonto enrich (replenish) above-lying hydrocarbon-bearing strata.

As a matter of fact, there takes place the formation of a new gasdeposit or a gas pool constituted this time by a gas-filled andreplenished storage reservoir.

On this occasion, the non-uniformity of gas liberation from the originalgas-saturated water-bearing horizon becomes immaterial, as it is alsoimmaterial in the geologic processes of the formation of gas deposits,whereas the gas pool thus-formed may be directly used as a sufficientlystable source of gas supply.

The considerable extent of gas-saturated water-bearing horizons which,owing to the present invention, potentially become usable for industrialgas production makes it possible, with a certain degree of freedom, toselect specific areas for the formation of a storage reservoir abovesuch horizons and, accoridngly, to select areas for exerting periodicde-gassing effects on these horizons. It is but natural that the choiceof an area in the vicinity of a potential gas user may be regarded asone of most likely alternative choices, since it affords savings on gastransporation.

The very possibility for making a choice also makes it possible to forma storage reservoir over a gas-saturated water-bearing horizon atlocations of natural or artificial sources of elastic vibrations. Morespecifically, it may be the choice of a seismically active area or aregion situated in the vicinity of functioning hydroelectric powerstations, railways, military test fields, quarries in which blasts takeplace, industrial enterprises, etc. On all such occasions, within thearea in which gas is liberated to fill up a storage reservoir, anunderlying gas-saturated water-bearing horizon is subjected to theaction of elastic vibrations generated by the above-mentioned sources,thereby diminishing the need for the above-described artificial effectsand, consequently, reducing power consumption for gas production.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically represents one of the embodiments of the process inaccordance with the present invention, wherein a local source sunk intoa horizon through a gas well exerts a de-gassing effect on agas-saturated water-bearing horizon.

FIG. 2 represents another embodiment of the method of the invention,wherein a gas-saturated water-bearing horizon is subjected to thecombined action of different sources exerting a de-gassing effect.

FIG. 3 illustrates yet another embodiment of the method of theinvention, wherein a storage reservoir over a gas-saturatedwater-bearing horizon is formed in the vicinity of a source of naturalor artificial vibrations.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

At least one well (2) (FIG. 1) is sunk over a gas-saturatedwater-bearing horizon (1) in an area which is convenient for operationor selected for some other considerations. To be able to receive gasbeing liberated, works are undertaken to form an artificial cavity abovethe horizon, i.e. a storage reservoir (3). At the same time, means areprovided for subsequent gas take-off from the storage reservoir byforming a perforated portion (4) of the gas well (2).

Thereupon, the gas-saturated water-bearing horizon is subjected toextraneous effects. In accordance with one of the embodiments of thepresent invention, a gas-saturated water-bearing horizon is subjected tothe effect of electric discharges produced by a spark gap shownschematically as a source (5) of local degassing effects. An explosivecharge may also constitute a source of local degassing effects. Inaccordance with another embodiment of the present invention, a horizonis subjected to the action of an electromagnetic field generated byelectrodes (6) sunk into specially drilled auxiliary boreholes shown inFIG. 2. Extraneous effects may be also exerted with the help of a source(7) of elastic vibrations situated on the day surface (FIG. 2). In allof these embodiments, the efficiency of extraneous effects is enhancedby providing a pressure difference, for instance, by partial take-off ofwater through the gas well (2), thereby reducing the pressure in thewater-bearing horizon.

As stated above, extraneous effects may be combined, as shown in FIG. 2.

Moreover, when forming a storage reservoir in the vicinity of natural orartificial sources of elastic vibrations, as schematically shown in FIG.3, it becomes possible to significantly lower the need for exertingadditional special-purpose degassing effects, since seismic elasticwaves, by acting upon a gas-saturated water-bearing horizon, promote andconsiderably intensify the gas liberation process.

In all of the above-described alternative embodiments for exertingextraneous degassing effects, the gas contained in a gas-saturatedwater-bearing horizon starts liberating itself. Since the specificgravity of gas is lower than that of water, gas ascends, accumulateswithin the storage reservoir, and may be extracted therefrom through theperforated portion of the gas well.

To carry out the method in accordance with the present invention, a gaswell(2) 1,200 m deep is sunk to reach a gas-saturated water-bearinghorizon characterized in the following parameters:

    ______________________________________                                        Occurrence depth     1,000-1,500 m                                            Water-bearing pool capacity                                                                        500 m                                                    Specific volume of   1.5-2 cub.m/cub.m                                        dissolved gas                                                                 Composition of                                                                dissolved gas, including:                                                     CH.sub.4             95-98%                                                   C.sub.2 H.sub.6 --C.sub.5 H.sub.12                                                                 0.5-0.3%                                                 Stratal (seam) pressure                                                                            10-15 MPa                                                Stratal temperature  20° C.                                            Water density        1.011                                                    ______________________________________                                    

A storage reservoir (3) is formed by the per se known methods at theboundary between clay and sandy strata (fractures needs sealing, andthis was done by grouting). A vibrations source (S) was sunk with theaid of a cable-rope through the gas well into the water-bearing horizon(1). Next, the horizon was subjected to the action ofvibratory/undulatory effects using the procedure shown in FIG. 1. In thecourse of passage of elastic vibrations (and afterwards) through thewater-bearing horizon, the gas dissolved therein starts liberating.Owing to its smaller specific gravity as compared to water, the gasascends, accumulates in the storage reservoir to be later lifted to theday surface through the perforated portion of the gas well (4), the gastake-off conditions through the well being controllable.

Let us now examine an embodiment of the method of the invention in aseismically active area illustrated in FIG. 3, in which a gas-saturatedwater-bearing horizon occurring at the level of the Jurassic formationis characterized in the following parameters: water containing calciumchloride with a total mineralization of from 91 to 147 g/liter, watercontians elevated iodine concnetrations (1-12 mg/l) and bromineconcentrations (294-426 mg/l). Stratal water features a high degree ofgas saturation (2,581-3,172 n.cm.³ /liter). Water-dissolved gases arepredominantly methanic, and their concentraiton reaches 83-95%. Theheavy hydrocarbon concentration does not exceed 5%. The gases alsocontain nitrogen (10%) and acid components (up to 0.5%), total pressureof dissolved gases reaching 21-51 MPa.

To carry out this particular embodiment of the method of the presentinvention, a borehole about 3,000 m deep is drilled. A storage reservoiris formed as described above to accumulate therein the gas liberated asa result of seismic effects. Upon expiration of a period of settling andestablishing a gas/water interface, it is possible to proceed to gastake-off. The gas take-off rate from the storage reservoir depends uponthe advance of the gas/water contact front (GWC) and is determined bythe GWC position. The gas take-off is effected from the head portion ofthe storage reservoir, whereas its tail portion is used for the GWCposition control by the geophysical methods. If no seismic phenomena arefelt for long periods of time, recourse is made to some of theabove-described methods to exert additional degassing effects.

Hence, the method in accordance with the present invention makes itpossible to solve simultaneously the problems of gas recovery, gascollection and gas storing, and all this in the immediate vicinity togas consumers.

The method in accordance with the present invention offers the followingadvantages: to bring into industrial turn-over such gas volumes as hadbeen regarded hitherto as unusable and irretrievable; to form gas pools,including gas pools located close to gas consumers; to solve in theoptimum manner the gas storing problem; to combine the problems of gasconsumers and those of a gas production field into an integral whole toform a common automatic control system to carry out more effectivelycontrol of gas production and supply processes; to reduce the number ofthe servicing personnel; to curtail material, financial, power and otherexpenses, including minimizing the distances over which gas (andequipment) must be transported, due to dispensing with the need forconstruction of trunk pipelines, pump stations, gas storage facilities,etc. The method of the present invention offers an additional advantageof providing greater safety for the environment, since it rendersunnecessary long-distance gas transportation. The method of the presentinvention may offer yet other advantages stemming out of the aboveSpecification.

What is claimed is:
 1. A process for producing gas from a gas-saturatedwater-bearing horizon comprising:drilling a well in a region of saidgas-saturated water-bearing horizon, forming an artificial storagereservoir above said gas-saturated water-bearing horizon communicatingwith said well, communicating the artificial storage reservoir with saidgas-saturated water-bearing horizon, periodically applying a degasifyingaction to said gas-saturated water-bearing horizon, periodically fillingsaid artificial storage reservoir with gas liberated from saidgas-saturated water-bearing horizon due to said periodical degasifyingaction.
 2. A process for producing gas from a gas-saturatedwater-bearing horizon,drilling a group of wells in a region of saidgas-saturated water-bearing horizon, using at least one well of saidgroup of wells for forming at least one artificial storage reservoirabove said gas-saturated water-bearing horizon, wherein said at leastone artificial storage reservoir communicates with said at least onewell, communicating the at least one artificial storage reservoir withsaid gas saturated water-bearing horizon, periodically applying adegasifying action to said gas-saturated water-bearing horizon,periodically filling the at least one artificial storage reservoir withgas liberated from said gas-saturated water-bearing horizon due to saidperiodic degasifying action, periodically recovering gas from said atleast one artificial storage reservoir through said at least one wellfrom said group of wells.
 3. A process as claimed in claim 2, whereinforming said at least one artificial storage reservoir includesincreasing the porosity and gas-permeability of rock above saidgas-saturated water-bearing horizon in the vicinity of at least one wellof said group of wells by means of an explosion.
 4. A process as claimedin claim 2, wherein forming said at least one artificial storagereservoir includes creating a plurality of cavities in a geologicformation above said gas-saturated water-bearing horizon by washing outcaverns in said geologic formation.
 5. A process as claimed in claim 2,wherein forming said at least one artificial storage reservoir includescreating a plurality of cavities in a geologic permafrost formationabove said gas-saturated water-bearing horizon by thawing out sectionsof said geologic formation.
 6. A process as claimed in claim 4, whereinforming said artificial storage reservoir includes packing walls androof of said artificial storage reservoir.
 7. A process as claimed inclaim 2, wherein a further artificial storage reservoir is formed abovesaid gas-saturated water-bearing horizon and communication is effectedbetween said artificial storage reservoirs.
 8. A process as claimed inclaim 2, wherein said periodical degasifying action is effected byacting on said gas-saturated water-bearing horizon with elasticvibrations to initiate the liberation of gas from said gas-saturatedwater-bearing horizon in said at least one artificial storage reservoir.9. A process as claimed in claim 8, wherein the frequency of saidelastic waves is within the range of from 0.1 Hz to 60 Hz.
 10. A processas claimed in claim 2, wherein said periodical degasifying action iseffected by acting on said gas-saturated water-bearing horizon with anelectromagnetic field to initiate the liberation of gas from saidgas-saturated water-bearing horizon in said at least one artificialstorage reservoir.
 11. A process as claimed in claim 10, wherein atleast two electrodes are used, each of said electrodes is positioned ina corresponding well of said group of wells to produce anelectromagnetic field, and the produced electromagnetic field is appliedto said gas-saturated water-bearing horizon.
 12. A process as claimed inclaim 2, wherein said periodical degasifying action is effected bysimultaneously acting on the gas-saturated water-bearing horizon withelastic vibrations and an electromagnetic field to initiate theliberation of gas from said gas-saturated water-bearing horizon in saidat least one artificial storage reservoir.
 13. A process as claimed inclaim 2, including heating a section of said gas-saturated water-bearinghorizon by injecting aqueous steam into said water-bearing horizonthrough one well of said group of wells.
 14. A process as claimed inclaim 2, including creating a pressure difference between saidwater-bearing horizon and at least one artificial storage reservoir byproducing liquid and/or gas from said artificial storage reservoir. 15.A process as claimed in claim 2, including determining the position ofthe gas-water interface in said artificial storage reservoir during thestep of filling said artificial storage reservoir with gas.
 16. Aprocess for producing gas from a gas-saturated water-bearing horizoncomprising the following steps:drilling a group of wells in the regionof said gas-saturated water-bearing horizon, using at least one well ofsaid group of wells to form at least one artificial storage reservoirabove said gas-saturated water-bearing horizon by increasing theporosity and gas-permeability of the rock above said gas-saturatedwater-bearing horizon in the vicinity of at lest one well of said groupof wells, communicating said at least one artificial storage reservoirwith said gas-saturated water-bearing horizon, periodically applyingdegasifying action to said gas-saturated water-bearing horizon byapplying elastic vibrations having a frequency of from 0.1 Hz to 60 Hzto said water-bearing horizon to initiate liberation of gas from saidgas-saturated water-bearing horizon in said at least one artificialstorage reservoir, periodically filling the formed at least oneartificial storage reservoir with gas liberated from said gas-saturatedwater-bearing horizon due to the effect of said periodical degasifyingaction, determining the position of the gas-water interface in saidartificial storage reservoir while it is being filled with gas, andperiodically recovering gas from said at least one artificial storagereservoir through another at least one well of said group of wells whenthe gas-water interface reaches a predetermined position.
 17. A processas claimed in claim 16, including creating a pressure difference betweensaid water-bearing horizon and at least one artificial storage reservoirby producing liquid and/or gas from said storage reservoir.
 18. Aprocess as claimed in claim 16, wherein said forming at least oneartificial storage reservoir includes increasing the porosity andgas-permeability of the rock above said gas-saturated water-bearinghorizon in the vicinity of at least one well of said group of wells bymeans of an explosion.
 19. A process as claimed in claim 16, whereinsaid forming at least one artificial storage reservoir includes creatinga plurality of cavities in a geologic formation above saidgas-saturating water-bearing horizon by means of washing out caverns insaid geologic formation.
 20. A process as claimed in claim 16, whereinsaid forming at least one artificial storage reservoir includes creatinga plurality of cavities in a geologic permafrost formation above saidgas-saturated water-bearing horizon by means of thawing out sections ofsaid geologic formation.
 21. A process as claimed in claim 16, whereinhydrodynamic communication is effected between said artificial storagereservoirs.
 22. A process as claimed in claim 16, includingsimultaneously acting locally on said gas-saturated water-bearinghorizon by means of a first source of elastic vibrations positionedinside the horizon and acting seismically on said horizon by means of asecond source of elastic vibrations positioned on the surface of theearth.